Riley Lambert

Riley Lambert

1564738790

Flutter and the Command Line

Let’s dive into the Flutter CLI (Command Line Interface) and see how we can improve our workflow

Using an IDE such as IntelliJ’s Android Studio or Visual Studio Code for developing Flutter apps makes our lives easier. At a push of a button, we can deploy our app, debug it, hot-reload, etc… And although we can have hotkeys to dismiss using the mouse, it can be troublesome having to move your mouse all around the screen. Or, you just like using the terminal or are curious about it and want to know different ways to interact with Flutter.

Thankfully Flutter comes with a handy CLI (Command Line Interface) that lets us easily do the same tasks that you would on any IDE, such as $ flutter doctor which shows if everything went fine and dandy with our Flutter Installation and checks the latest updates from the Flutter Github repository.

Flutter doctor

So let’s dive into the CLI to see what we can use on an everyday basis.

Exploring the Help section

Using $ flutter help will show us a long and intimidating list of commands, such as analyze, build, channel, clean, create, install, logs, pub and run, each with a small description. But how can we use each command?

As with many other CLI, we can use the helpful -help argument after any command to prompt the CLI to show us a small help screen.

Flutter Help reduced log

In this present case, if we use the following command:

$ flutter analyze --watch --no-pub

We will analyze the code from the current Flutter project “/continuously, watching the filesystem for changes/” ( -watch) and without getting or updating our dependencies from pub --no-pub.

Running our Projects

When developing any type of application, the one thing every developer needs is to run their code. After all, how can we marvel at what we have done (or despair as each new bug tries to underpin our progress)?

For that, all we have to do is use the simple command:

$ flutter run

Which is simple enough to use, right? But sometimes we may have more than one device (or simulator) connected to our machine, and so the following error message appears:

Flutter run with more than one device attached

So let’s do as we are told and use the correct flag for our device using -d <device id>. Assuming that our device id is emulator-4, we can run our project to that device using:

$ flutter run -d emulator-4

Now, this is where things get interesting. Let’ say that our app users Flavors and we have different entry points for our app: main.dart and main_dev.dart for prod and dev flavors/schemes. How can we run each one of them? Let’s use the -help command and search for arguments that may help us.

Flutter run help

As seen above, we can use the --flavors and -t flags to help us choose a Flavor and an entry point, respectively. As such, we can have two different commands for running our app:

$ flutter run -d emulator-4 -t lib/main_dev.dart --flavor dev$ flutter run -d emulator-4 -t lib/main.dart --flavor prod

This will get our app up and running! 🚀

But… something is missing.

Flutter is known for the Hot Reload feature, that we can easily access in our favourite IDE, most of the times by clicking in a ⚡ symbol. But how can we do that with the command line? The only reference to hot reload we have is in the --hot argument, but that only lets us enable or disable that function.

If we pay close attention to the console output when we run our app, we see that it does mention the Hot Reload and Hot Restart features. Only, instead of using named arguments, the command line is prompting us to type each character as we need it.

Flutter run output

So let’s follow its instructions and click on r.

Hot reload

And how we can hot restart? Using Shift + R

Hot restart

And that’s it! But, what other functionalities are hidden behind the run command? We can check them out by using the h key.

Detailed help for Flutter run

So, for instance, if we click on p we will have a helpful UI overlay with the construction guidelines for each widget, which can prove useful when trying to fix nasty UI bugs.

Flutter app with widget construction lines

(Protip: this screenshot was taken using the s key, which saves a screenshot in the project directory)

Flutter Channel

Another useful command from the Flutter CLI is the ability to change the current Flutter channel. A channel is nothing more than the git branch in which we are getting Flutter’s source code. When do we need to change it? When we are using experimental features, such as Flutter Web or if we can’t wait for a specific bug-fix to land in the stable channel.

Flutter channels — stable channel currently selected

After we change a channel via $ flutter channel master, we should always use the $ flutter doctor command to verify if the Flutter tools are correct or if we need to upgrade our version of Flutter, which we can do by using $ flutter upgrade.

Flutter Logs

$ flutter logs -d emulator-4

This one is quite explanatory: it shows the flutter logs for the device. But not just the Flutter logs for the current running app, but for all apps that use Flutter in the connected device.

Flutter logs help

Why is this helpful?

  • This can help us verify if in the --release version of the app (or even the version sent to the app/play store) has any logs that we forgot to hide
  • It can help us save time to see the logs of the current app without needing to re-run the app.
  • If for some reason $ flutter run outputs the system’s logs alongside Flutter logs, you can open a new terminal tab and run $ flutter logs to see just the Flutter logs for that device.

Creating a New Project

Running a project and changing the Flutter channel can be pretty cool, but all that is for nothing if we don’t have a project to test them on!

When creating a project we might be interested in:

  • Giving it a name
  • Assign an organisation for the bundle name (example: com.vanethos)
  • The language used for the Android project (Kotlin or Java)
  • The language used for the iOS project (Swift or Objective-C)

Thankfully, we can find a solution for each of them in the following arguments:

Flutter Create Help

Thus, to create a new project in the flutter_cli_test folder with the bundle prefix com.vanethos , project name clitest and using Kotlin and Swift, without AndroidX we need to use:

$ flutter create --org com.vanethos --project-name flutter_cli_test -a kotlin -i swift flutter_cli_test

And, if we didn’t know how to run our project, Flutter guides us into running it directly from the command line, which is pretty neat!

Flutter create help

Creating Custom Scripts in Bash

We know how to create and run projects, and if we look into the help section we also know how to clean our code (using $ flutter clean).

However, our principles tell us that for each run of the project we must:

  • Clean the Android project
  • Clean the Flutter Project
  • Run the dev flavour of our app in our favourite device

Which require us to type the following in the terminal:

cd android
./gradlew clean
cd ..
flutter clean
flutter run --flavor dev -t lib/main_dev.dart -d emulator-4

What if we could just type in a single command to run the app in each flavour?

In MacOs, we might want to research how to create bash scripts. Thankfully Tania Rascia made a great article , in which we can see that in order to create a bash script we need to create a file where in the first line we add the following:

As such, we can now create a simple bash script by:

  • Creating a file called dev_build.sh (we can do it with the command touch dev_build.sh
  • Adding the following to the file:
#!/bin/bash
cd android
./gradlew clean
cd ..
flutter clean
flutter run --flavor dev -t lib/main_dev.dart -d emulator-4

How can we run it? Simply by calling the file using:

$ sh dev_build.sh

And voila! We can now with a single command clean our code thoroughly and deploy our app in a specific flavour!

Bonus Tip: Using Pubx

Let us take our love for the command line even a step further: we want to search for packages and add them to our pub spec.yaml file?

Though Flutter does not allow this natively, we can rely on the Flutter Community to meet our wishes, and meet them they have with the pubx package by Scott Hyndman.

Want to search for a specific package? Use $ pubx search provider

pubx search

Found a package and want to know more about it? Use $ pubx view provider

pubx view

And finally, want to add dependencies to your pub spec.yaml file from the command line? Easily done with the $ pubx add provider

Conclusion

We’ve gone through a brief introduction to the Flutter CLI 💻.

It’s up to us to choose if this is the right option for us or not. Maybe we like to use the terminal, maybe we just want to use the IDE and have it deal with it, none should judge us about that. However, it’s always good to know the alternatives. Why?

  • With the command line we can run project without opening them
  • We can easily change the Flutter Channel
  • We can analyze our code before a big commit
  • If we quickly want to test a new plugin/package we can do it easily via:
$ git clone https://github.com/Vanethos/stream_disposable.git
$ cd stream_disposable/examples
$ flutter run

  • You can easily create new release builds of your app via
$ flutter build ios
$ flutter build appbundle

  • It just looks cool

Tell me your opinion about this! 😄 Are you going to use it? What are your favorite commands?

#flutter #mobile-apps

What is GEEK

Buddha Community

Flutter and the Command Line

Google's Flutter 1.20 stable announced with new features - Navoki

Flutter Google cross-platform UI framework has released a new version 1.20 stable.

Flutter is Google’s UI framework to make apps for Android, iOS, Web, Windows, Mac, Linux, and Fuchsia OS. Since the last 2 years, the flutter Framework has already achieved popularity among mobile developers to develop Android and iOS apps. In the last few releases, Flutter also added the support of making web applications and desktop applications.

Last month they introduced the support of the Linux desktop app that can be distributed through Canonical Snap Store(Snapcraft), this enables the developers to publish there Linux desktop app for their users and publish on Snap Store.  If you want to learn how to Publish Flutter Desktop app in Snap Store that here is the tutorial.

Flutter 1.20 Framework is built on Google’s made Dart programming language that is a cross-platform language providing native performance, new UI widgets, and other more features for the developer usage.

Here are the few key points of this release:

Performance improvements for Flutter and Dart

In this release, they have got multiple performance improvements in the Dart language itself. A new improvement is to reduce the app size in the release versions of the app. Another performance improvement is to reduce junk in the display of app animation by using the warm-up phase.

sksl_warm-up

If your app is junk information during the first run then the Skia Shading Language shader provides for pre-compilation as part of your app’s build. This can speed it up by more than 2x.

Added a better support of mouse cursors for web and desktop flutter app,. Now many widgets will show cursor on top of them or you can specify the type of supported cursor you want.

Autofill for mobile text fields

Autofill was already supported in native applications now its been added to the Flutter SDK. Now prefilled information stored by your OS can be used for autofill in the application. This feature will be available soon on the flutter web.

flutter_autofill

A new widget for interaction

InteractiveViewer is a new widget design for common interactions in your app like pan, zoom drag and drop for resizing the widget. Informations on this you can check more on this API documentation where you can try this widget on the DartPad. In this release, drag-drop has more features added like you can know precisely where the drop happened and get the position.

Updated Material Slider, RangeSlider, TimePicker, and DatePicker

In this new release, there are many pre-existing widgets that were updated to match the latest material guidelines, these updates include better interaction with Slider and RangeSliderDatePicker with support for date range and time picker with the new style.

flutter_DatePicker

New pubspec.yaml format

Other than these widget updates there is some update within the project also like in pubspec.yaml file format. If you are a flutter plugin publisher then your old pubspec.yaml  is no longer supported to publish a plugin as the older format does not specify for which platform plugin you are making. All existing plugin will continue to work with flutter apps but you should make a plugin update as soon as possible.

Preview of embedded Dart DevTools in Visual Studio Code

Visual Studio code flutter extension got an update in this release. You get a preview of new features where you can analyze that Dev tools in your coding workspace. Enable this feature in your vs code by _dart.previewEmbeddedDevTools_setting. Dart DevTools menu you can choose your favorite page embed on your code workspace.

Network tracking

The updated the Dev tools comes with the network page that enables network profiling. You can track the timings and other information like status and content type of your** network calls** within your app. You can also monitor gRPC traffic.

Generate type-safe platform channels for platform interop

Pigeon is a command-line tool that will generate types of safe platform channels without adding additional dependencies. With this instead of manually matching method strings on platform channel and serializing arguments, you can invoke native class and pass nonprimitive data objects by directly calling the Dartmethod.

There is still a long list of updates in the new version of Flutter 1.2 that we cannot cover in this blog. You can get more details you can visit the official site to know more. Also, you can subscribe to the Navoki newsletter to get updates on these features and upcoming new updates and lessons. In upcoming new versions, we might see more new features and improvements.

You can get more free Flutter tutorials you can follow these courses:

#dart #developers #flutter #app developed #dart devtools in visual studio code #firebase local emulator suite in flutter #flutter autofill #flutter date picker #flutter desktop linux app build and publish on snapcraft store #flutter pigeon #flutter range slider #flutter slider #flutter time picker #flutter tutorial #flutter widget #google flutter #linux #navoki #pubspec format #setup flutter desktop on windows

Terry  Tremblay

Terry Tremblay

1598396940

What is Flutter and why you should learn it?

Flutter is an open-source UI toolkit for mobile developers, so they can use it to build native-looking** Android and iOS** applications from the same code base for both platforms. Flutter is also working to make Flutter apps for Web, PWA (progressive Web-App) and Desktop platform (Windows,macOS,Linux).

flutter-mobile-desktop-web-embedded_min

Flutter was officially released in December 2018. Since then, it has gone a much stronger flutter community.

There has been much increase in flutter developers, flutter packages, youtube tutorials, blogs, flutter examples apps, official and private events, and more. Flutter is now on top software repos based and trending on GitHub.

Flutter meaning?

What is Flutter? this question comes to many new developer’s mind.

humming_bird_dart_flutter

Flutter means flying wings quickly, and lightly but obviously, this doesn’t apply in our SDK.

So Flutter was one of the companies that were acquired by **Google **for around $40 million. That company was based on providing gesture detection and recognition from a standard webcam. But later when the Flutter was going to release in alpha version for developer it’s name was Sky, but since Google already owned Flutter name, so they rename it to Flutter.

Where Flutter is used?

Flutter is used in many startup companies nowadays, and even some MNCs are also adopting Flutter as a mobile development framework. Many top famous companies are using their apps in Flutter. Some of them here are

Dream11

Dream11

NuBank

NuBank

Reflectly app

Reflectly app

Abbey Road Studios

Abbey Road Studios

and many more other apps. Mobile development companies also adopted Flutter as a service for their clients. Even I was one of them who developed flutter apps as a freelancer and later as an IT company for mobile apps.

Flutter as a service

#dart #flutter #uncategorized #flutter framework #flutter jobs #flutter language #flutter meaning #flutter meaning in hindi #google flutter #how does flutter work #what is flutter

Adobe XD plugin for Flutter with CodePen Tutorial

Recently Adobe XD releases a new version of the plugin that you can use to export designs directly into flutter widgets or screens. Yes, you read it right, now you can make and export your favorite design in Adobe XD and export all the design in the widget form or as a full-screen design, this can save you a lot of time required in designing.

What we will do?
I will make a simple design of a dialogue box with a card design with text over it as shown below. After you complete this exercise you can experiment with the UI. You can make your own components or import UI kits available with the Adobe XD.

#developers #flutter #adobe xd design export to flutter #adobe xd flutter code #adobe xd flutter code generator - plugin #adobe xd flutter plugin #adobe xd flutter plugin tutorial #adobe xd plugins #adobe xd to flutter #adobe xd tutorial #codepen for flutter.

Brain  Crist

Brain Crist

1602147600

Flutter App Development Trends 2020

As the new decade dawns upon us, a slew of technologies has been making a lot of noise to grab the developers’ attention. While native app development is going strong, the trade winds are now blowing towards going cross-platform.

Adobe PhoneGap, React Native, Xamarin and Ionic are all leaving no stone unturned to be the undefeated champion of cross-platform development. Still, Google’s Flutter is all set to take them all on at once.

There are a tonne of resources available online to learn about Flutter, and you can start with this step by step flutter guide.

With reduced code development time, increased time-to-market speed, near-native performance, and a bevy of advantages under its hood, Flutter is set to dominate the market this decade.

Before we take a look at trends making the Flutter race ahead in 2020, let us do a quick recap of what Flutter is, for those who have been living under a rock.

#flutter #flutter-for-mobile-app #flutter-app-development #mobile-app-development #flutter-trends #software-development #advantages-of-flutter-mobile #pros-and-cons-of-flutter

Juned Ghanchi

1621572917

Flutter App Development Company India, Flutter App Developers for Hire

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